The present invention relates to a pushbutton for electronic timepieces and more particularly for electronic wristwatches.
The conventional pushbutton for operating a switch provided in a electronic wristwatch comprises a guide pipe secured to the watch case and a button body slidably provided in the pipe. The button body has a circumferential annular groove with which an O-ring is engaged to provide a watertight seal between the pipe and the button body. In such a structure, the button body must have a diameter sufficient to provide the annular groove and also to have necessary strength in the remaining reduced diameter portion. To meet such a requirement, the button body cannot be constructed to be of a small diameter.
On the other hand, the electronic wristwatch has been improved to decrease its thickness and size. Under such circumstances, problems have arisen in that such a large conventional pushbutton is not suited for a wristwatch of reduced size. In addition, the design for the case of a wristwatch is restricted by the pushbutton when attempting to make a wristwatch of reduced size.